Add Value.def to the list of textual includes, excluding it from the modules build.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240823 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/module.modulemap

@@ -124,6 +124,7 @@ module LLVM_IR {
   textual header "IR/DebugInfoFlags.def"
   textual header "IR/Instruction.def"
   textual header "IR/Metadata.def"
+  textual header "IR/Value.def"
 }
 
 module LLVM_IRReader { requires cplusplus umbrella "IRReader" module * { export * } }